This invention relates to tools for cutting insulation on electrical wiring and in particular to a tool suitable for stripping insulation from an end portion of electrical wiring.
A number of tools are known for stripping insulation from electrical wiring. A well known and commonly used type of wire stripper is that shown and taught by U.S. Pat. No. 3,130,616. This tool teaches the use of a pair of cutting members, each of which forms a handle and has a cutting edge formed on one end. Each cutting edge has a V-shaped notch formed therein. The notches have sharpened edges and are adapted to cooperate to cut the insulation covering. The two cutting members are pivotally connected together by a pin member located close to the cutting edges. Mounted on the side of one of the cutting members is an adjustable stop provided to limit the movement of handles and thereby the cutting edges. Proper use of the stop prevents the metal wires in the wiring from being damaged. The aforementioned patent also teaches the use of a return spring which urges the handles apart.
U.S. Pat. No. 3,172,133 teaches a set of long nose pliers that can be used to strip electrical wiring. The wiring is stripped by use of notches providing on the pliers.
U.S. Pat. No. 3,336,666 dated Aug. 22, 1967 teaches an insulation cutting tool that is quite complex in its construction. The tool is designed to hold the wire being cut on both sides so that the inner wire will not be damaged. In the patent a jacket engaging device moves with the blade until the jacket is firmly engaged by the device. Then the device remains stationary as the blade moves further to cut the jacket.
A tool that is sold as a "wire stripper" is made by Ideal Industries Inc. of Sycamore, Ill., U.S.A. This tool has a series of notches along each of two cutting blades that are pivotally connected together. The notches accommodate electrical wiring of various standard sizes. Stop members formed on the handles of the tool prevent the cutting edges from severing the metal wire or wires in the insulation. With this tool it is necessary to pull the insulation off the wire or wires by pulling sideways on the tool after the insulation has been cut.
A rather complex automatic wire stripper is sold and distributed by Radio Shack, a division of Tandy Corporation. With this tool there is a pair of wire gripping jaws that holds the electrical wiring while the insulation is being cut by a separate set of blades having a series of notches formed therein. Again the notches accommodate standard electrical wiring of various sizes. The two blades do not close on each other until after the wire gripping jaws have engaged the electrical wiring. After the blades have cut the insulation, further movement of the two handles of the tool towards one another causes the blades to pivot away from the wire gripping jaws and this results in the insulation being stripped from the wire or wires.
An object of the present invention is to provide a wire stripping tool that will not only cut the insulation around the electrical wire or wires but will also remove the severed piece of insulation from the wire or wires.
A further object of the present invention is to provide a wire stripping tool capable of both cutting the insulation and removing it in a very efficient manner from the wire or wires extending through the severed piece of insulation, which tool is simple and reliable in its construction.